ASUS P5N-E SLI Problems

I'm having trouble with my Dad's old computer, the problem is it would fail to stay on for more than 30mins and then randomly switch off, showing a blue screen for less than a second. I've taken all the dusty components out, cleaned them and put them back in, also I've replaced the thermal paste to the CPU, so I'm certain it's not an overheating issue. But the problem still prevails, one thing I have noticed is that there is a strange beep that stays on for about a second upon booting. Would appreciate some help Thanks.

Also I will publish some more system specs if that would help.

Few things randomly come to mind:

  • Check if the capacitors on the mobo are bulging or poped, mobo could be failing
  • Try removing one stick of memory and running it, if it fails try the other, one  (or both) sticks of mem could be failing
  • Try booting the computer with a linux boot disk, run it for a while doing random things (could stress test), this could eliminate both HDD issues and software issues
  • If you have a spare PSU, could always try switching it out, but this seems unlikly to be the issue

Thanks for the advice

It wouldn't hurt to check the compaciters in the power supply to see if they are leaking,buldging or leaking